1. Field
Directed carbon nanotube growth is described, and in particular growing carbon nanotubes with a well-controlled direction, orientation and size.
2. Related Art
Carbon nanotubes (CNT) have been investigated for a wide range of possible applications. However, at present, it remains difficult to control the size of CNT, both in diameter and length. Size is an important factor in the electrical properties as well as the mechanical properties of the device. It is also difficult to control the chirality of a CNT which affect the CNT's transport properties. The placement and orientation of a CNT is also not well controlled. Without a way to reliably and inexpensively control the size, distribution, and growth direction of nanotubes to within a few nanometers, their applications are limited.
One such application is in making discrete CNT transistors. Prototype transistors have been shown to exhibit a variety of promising transport properties. Field effect transistors (FET) made with CNTs have shown very high thermal conductivity, high current conduction, and very high gain compared with silicon devices. However, these prototypes cannot yet be manufactured with the cost, precision, and reliability of conventional technologies, such as mature silicon based CMOS (complementary metal oxide semiconductor) technology.